Producing vessels of quartz or similar material difficult to fuse and impermeable for gases



Patented Get. 21, 1924-.

UNITED-STATES A 1,512,511 PATENT OFFICE.

ZACI-IARIAS VON HIRSGHIBERG, OF BERLIN-PANKOW, G'rERIVIANY.v

PRODUCING VESSELS or QUARTZ on SIMILAR MATERIAL. DIFFICULT T0 rnsn AnnIMPERMEABLE non GASES.

N0 Drawing.

7 '0 all whom it may concern Be it known that I, ZACHARIAS VONHinsorinnnc, citizen of Russia, residing at Berlin-Pankow, Germany, haveinvented new and useful Improvements in Producing Vessels of Quartz orSimilar Material Difficult to Fuse and Impermeable for Gases.

It is very well known to produce a hollow cylindrical melt by fusingquartz and similar materials in an electric resistance furnace and toshape these melts after closing one end of the melt by drawing orblowing into dishes, crucibles and so on. For this purpose a mould isused, consisting of several hollow moulds, into which the melt cylinderis blown by means of compressed air. By this process a final product isobtained showing a continuous piece comprising as many hollow vessels asthere are single moulds; though the articles produced are connected witheach other, they are divided from each other by comparatively widespaces. For the purpose of rendering the single articles impermeable forgases they must be mechanically disconnected and isolated. In such casethe objects are easily broken by cutting or tearing off; likewise thematerial remaining in the interval between two following articles islost. isolated hollow objects are rendered impermeable for gases byglazing their surfaces under the influence of a strong source of heat,as for instance by an oxyhydrogen gas-burner. Besides the above citeddrawbacks this process has the special disadvantage, that the separatedhollow articles do not possess a uniform thickness of the walls. Theyare thinner in their lower parts, than at the margin; therefore theymust be first ground off so that the wall becomes quite uniformthroughout.

The object of the present invention is a method by which all thesedrawbacks are dispensed with. The single hollow articles of quartz arenot first shaped and afterwards rendered impermeable for gases byenamelling, but are simultaneously shaped and enamelled, withoutproducing loss by breaking; a further grinding is unnecessary. I

For the purpose of embodying the new method a hollow cylindrical melt isproduced in the well known manner in the electric-resistance furnace andthen a tube is formed by drawing it in the usual manner.

Application filed June 30, 1922.

The

Serial No. 572,040.

By this drawing, tubes of a distinct diameter according to the stressand pressure are produced having a corresponding length and uniformthickness of wall. According to this invention such tube is thereafterdivided in its longitudinal direction into two equal halves;finally each half plece is transversely cut into a great number of fiatpieces or plates (which are more or less arch-shaped).

The plates thus produced show the same uniform thickness of wall, as thetube, from which they are derived.

Whereas the hollow body is immediately brought into the final shape forinstance into crucibles, dishes and the like by the former known processby blowing and thereafter finished by enamelling, the hollow body isaccording to the present invention first formed into a fiat plate whichfor instance is slightly arched, having not yet the characteristics ofthe final article but showing merely a kind of universal frame, which isthen subjected to the action of a strong source of heat, for instance anoXyhydrogen gas-burner, which exercises pressure on the final productand forces it on to the molds, thereby causing it to assume the shape ofcrucibles, dishes or the like and simultaneously glazing or enamellingthe product. The final product according to the known process is herereplaced by a universally shaped preliminary article, receiving in the)BIlOd of glazing or enamelling the final s ape.

The arched plate, produced by the division of a tube having the size ofthe final product is put upon the surface of a crucible or dish-shapedmould and then heated by a suitable strong source of heat for instanceby an oxyhydrogen gas-burner or an electric arc. By the combined actionof the temperature and pressure of the burner the shallow-concavo-convexblank is softened point by point stepwise in such a manner that thesurface is fritted, glazed and enamelled and thereby renderedimpermeable for gases. At the same time the plate accommodates itself tothe surface of the mould. In this manner the plate is formed into thehollow final product, i, e., into a crucible, dish or the like, finallyshaped and enamelled. Besides the cited technical advantages the costsof the meth- 0d are considerably diminished to nearly fifty per cent,because the breaking of the articles is avoided and the grinding reindered unnecessary.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 2- 1. A process of producing hollow products imperviousto gas and formed of a difiicultly fusible material, which consists inproducing a tube of the desired material, dividing said tubelongitudinally, cutting the individual halves of the tube crosswise intoajplurality of plates curved in cross sections, placing said plates onthe outer surface of a mold of the desired form, and subjecting theplates to the action of a strong source of heat and pressure, wherebythe plate is caused to assume the form. of the mold and issimultaneously glazed.

2. A process of producing hollow products impervious to gas and made ofquartz, which consists in producing a hollow cylindrical body of quartz,cutting said body longitudinally thereof into two equal parts, cuttingeach of said parts into a plurality of plates carved in cross sections,placing said plates upon the outer surface of a mold having the form otthe article to be, produced, and subjecting said plates to the action o1a strong source Oil heat and pressure thereby causing the plates toassume the form of the mold and siniultaneoiasly glazing the surfacethereot.

In testimony whereof I have signed in name to this specification in thepresence of two subscribing witnesses.

ZACHARIAS voN HI R SGHBERG.

lVitnesses E. HljLTZERMANN, LAURENCE A, Hansen.

